philosopher Aristotle has often been exaggerated. In medicine they recognized Galen as a greater authority than Aristotle. In astronomy Ptolemy was their guide. In natural history they cited Pliny the Elder. Indeed they used scores of other authorities than Aristotle. But had he been their sole source of information, they would not have been without interest in natural science, for Aristotle devotes much attention to that field. He wrote not only on logic, ethics and metaphysics; but on physics, animals, plants, minerals, the heavens, sleep and waking, generation and corruption, and so forth. Indeed, he was without much doubt the greatest scientist of antiquity.
Now the twelfth century had known only Aristotle's "Logic." When his other works were brought from Spain and translated from Arabic into Latin in the early thirteenth century, those devoted to nature created even more of a furore than the others. The great University of Paris at first prohibited these newly discovered books in natural philosophy. But it was impossible to check the rising tide of secular and scientific learning. Another French university at Toulouse advertised its readiness to teach these works of Aristotle on nature, and before long the forbidden books were being freely taught at Paris itself.
Paris's two leading theologians and commentators on Aristotle were also recognized in their own day as great students of nature. Albertus Magnus wrote on all the subjects that Aristotle had treated and added much new information in his works on plants and animals. Thomas Aquinas is usually thought of as a theologian; but when he died, the University of Paris wrote to the Dominicans asking that his bones might be sent to Paris for burial, and also requesting the transmission of some books begun by him while at the university but not as yet completed upon his departure from Paris. What were these writings; theological treatises, commentaries on the minor prophets, or manuals of devotion? None of these. They were a commentary on the philosopher Simplicius; another on Aristotle's treatise "The Sky and Universe"; a third on Plato's "Timæus," a dialogue dealing with nature; and finally, a treatise on irrigation and mechanical engineering.
Another erroneous notion concerning the middle ages is that nature was studied chiefly in order to illustrate spiritual truth or to teach moral lessons. The "Bestiary," a little manual about animals used by the clergy for illustrations in their sermons, is often referred to as typical of medieval science; but one might as well judge modern science by the lurid articles in the supplements of our Sunday newspapers. Far more typical are the long encyclopedias in Latin prose which collected all available information concerning the phenomena of nature, and whose motive was rather a keen curiosity about the things of this world than a desire merely to illustrate divine verities. It is true that one of the earliest and briefest of these encyclopedists, Alexander Neckam, an
